Fast Calculation of Cavity-Mode Characteristics of

A fast approach based on effective index perturba- tion method is proposed to evaluate the intrinsic characteristics of photonic-crystal-slab-based microcavity with two-dimensional finite-difference time-domain (2-D FDTD) technique. For two widely used single defect structures, less than 2% computational error was obtained in calculating the defect mode frequencies. Accurate prediction of cavity modal properties and resonant peak frequencies is feasible based on 2-D FDTD simulation by adjusting the effective index to match the dielectric band edge for donor-like defect mode. The correlation between the modified effective index and the cavity (lasing) mode with the highest quality factor offers an efficient tool in the design of defect mode based photonic crystal microcavities. Index Terms—Cavity quality factor, defect-mode cavity, effective index method (EIM), effective index perturbation (EIP), photonic crystal slabs (PCSs).